The fan/filter combo removes odor and purifies air by sucking the air in the room through the carbon filter and expelling it out of the room. (Rooms 8 x 8 & Under). The carbon filter is quality constructed with heavy-duty galvanized steel, these filters can be mounted vertically or horizontally and come with pre-filter to prolong the life of the carbon. When integrated into your exhaust system, all the air that leaves your growing environment it totally and completely scrubbed before exiting.